7.5% sounds reasonable, may be even too little if he is truly valuable candidate. Equity numbers are weird. Some times, 10% equity means the other founder has

7.5% sounds reasonable, may be even too little if he is truly valuable candidate. Equity numbers are weird. Some times, 10% equity means the other founder has 90% and any dilution is going to hit that... meaning that a 20% grant to someone else moves the split to 72/8/20 not 70/10/20. So it's important to know what events can trigger general dilution. If the option pool is not set aside, that will trigger dilution too. Sometimes, 10% means "I'm giving you 10 but I'm only giving myself 25 and the other 65 is for new talent, option pools, and to offset investor dilution". Other times, it means, "you're subject to all dilution, the only constant being that I have 9 times as much as you do". Two entirely different things.